Coffee co-fermentation gaining traction
Image: Atkinsons Coffee Roasters
Coffee consumption has been on a growth path globally with producers, coffee roasters and full-service restaurants looking for more innovative ways to meet the diverse coffee flavour needs of their customers.
The International Coffee Organization (ICO) reported that world coffee consumption increased by 4.2 percent to 175.6 million bags (60kg) in c offee year 2021/22 and by a further 1.7 percent to 178.3 million bags in 2022/23.
This increase in consumption, the ICO noted, is expected to trigger another year of deficit in the world market with an estimated shortfall of 7.3 million bags in coffee year 2022/23.
According to the ICO, Africa and Asia and Oceania’s consumption would expand by the most, increasing by 4.1 percent and 3.1 percent to 13.4 million bags and 44.2 million bags respectively. The two regions’ shares of world coffee consumption would, as a result, grow to 7.5 percent and 24.7 percent, respectively.
As consumption grows, coffee producers are endeavouring to sustain or improve the flavour of their coffee, especially during the post-harvest processing phase to satisfy the taste and volume demand of consumers. One of the trends that has recently gained traction among coffee producers is co-fermentation of coffee.
Image: Lucia Solis
What is Coffee Co-Fermentation?
US-based green coffee company, Ally Coffee, which connects roasters with specialty coffees sourced through sustainable partnerships, said these co-fermented coffees “offer distinct cup profiles defined greatly by added flavour agents in the fermentation process, imparting difficult-if-not-impossible to achieve flavours to the coffee.”
Ally Coffee, through its Ally Open, a platform for roasters to purchase a curated selection of mall-box specialty green coffee, said some of the coffee producers complete the processing of their crop with little-to-no additives leaving the fermentation process to the naturally occurring microbes and sugars from the coffee cherries.
However, there are others who “have adopted the use of extra ingredients during processing to achieve a number of results including batch consistency, labour efficiency, and differentiated flavour profiles.”
Co-fermentation, explained Joseph Rivera, senior research scientist at Ireland-based public food company, Kerry Group, is an emerging trend that could give coffee farmers control over their coffee fermentation “by intentionally infusing commercially available yeasts, such as Saccharomyces cerevisiae, commonly used in wine and baking to allow a more uniform colonisation of microbes in their tanks.”
Moreover, there is an increasing interest in co-fermenting coffee with fruits and spices such as orange peels, peaches, pineapples, cinnamon, and hops, among other additives.
“The addition of these non-coffee products alters the natural biome in the fermentation tank, introducing new flavours compounds such as terpenes, oils, ester, to ultimately create more complex flavours than traditional coffee fermentations,” added Rivera.
The putting of additives in the fermentation tank/bag, stated Vietnam’s processing and export firm, Helena Coffee, “will help control fermentation by providing sugar for existing microorganisms.” Furthermore, “it also enriches the microflora of the solution or changes its pH and thus regulates the type of microorganisms that will be active during the fermentation process,” Helena stated in a blog.
The co-fermentation process begins soon after harvesting of the coffee with farmers utilising either the washed or dry post-harvest process.
In the washed coffee, the coffee cherry is mechanically de-pulped thus removing the outer layer of skin or exocarp and exposes the encased coffee bean. The encasing of a thin sticky layer of mucilage must be removed to release the bean or endosperm locked inside the cherry.
The conventional method of removing the mucilage is placing the de-pulped coffee into a tank of water and allowing it to sit for 8-24 hours and in some extreme cases, up to 72 hours, explained Rivera. “Due to the presence of yeasts and bacteria naturally found on the surface of the cherry, the tank becomes inoculated whereby microbes begin to consume the sugar in the solution to create a wide host of acids, aldehydes and esters, hence driving the pH of the surrounding solution down and, along with the
pectinases, help dissolve the sticky mucilage off de-pulped coffee.”
Co-Fermented Coffee Challenges
The potential of allergens in co-fermented coffee has dominated discussion within the coffee industry, with some stakeholders suggesting more transparency when it comes to labelling co-fermented coffee.
“For the most part, co-fermenting does not introduce allergens into the fermentation stage,” said Rivera, “however, there have been reports of farmers experimenting with co-fermenting with ‘milk’ (here I’m broadly speaking of cow’s milk, but can also include almond, coconut, soy).”
There is a possibility, he added, of the non- coffee additives introducing allergens, although these novel fermentations have generally been confined to small scale research and development experiments.
Even if there were allergens, such as lactose and nut proteins present in the coffee, “we need to remember that coffee is roasted to ~200-250°C (~392- 482° F) during roasting, which effectively provides a potent ‘kill-step’ thereby rendering any, if not all, of any allergens inactive,” Rivera reminded.
The lack of consensus on allergens in co-fermented coffee is an indicator of existing concerns within the coffee industry that need to be addressed to ensure the safety of coffee
consumers.
Elsewhere, there exists a vacuum when it comes to approved standards on the labelling of co-fermented coffee that makes achieving transparency more challenging. But even then, some in the coffee sector are pushing for a little more clarity on all ingredients in co-fermented coffee.
“The Specialty Coffee Association (SCA), a non- legal organisation, has stated that co-fermented coffees will not be allowed in the barista competitions and must be clearly labelled if a non-coffee product has been added,” Riviera shared. He cited the most recent World Barista Competition rules and regulations which rule out coffee having any “additives, flavourings, colourings, perfumes, aromatic substances, liquids, powders, etc, of any kind added at any point between the time the coffee is picked (as cherry) to when it is extracted into beverage.”
Rivera said that these are just recommendations for now, but “we could see a push to legally define
labelling requirements and standards of identity for these emerging novel coffees in the future.”
However, the position by many coffee roasters further down the supply chain is that co-fermented coffees “should be clearly labelled if any non-coffee additives have been added for both safety and transparency.”
For example, the National Coffee Association of the United States said that due to the various
formulations, flavours, and preparation methods, coffee has become more complex, making labelling
“very complicated.” In many consuming markets, including the US, failure to label coffee properly “can lead to recalls that can impact your bottom line, your brand – and even pose a threat to your
customers.”
With global coffee consumption growing, more coffee producers, roasters and even foodservice
providers are expected to be more innovative in improving the flavours of the coffee cup with
co-fermentation probably becoming a major feature in post-harvest processes but more likely in a more regularised environment.
- Shem Oirere is a freelance business journalist based in Nairobi, Kenya. He has spent more than 25 years covering various sectors of Africa’s economy including the region’s agribusiness. He holds BA in InternationalRelations and Diplomacy from the University of South Africa and earned a higher degree in journalism from the London School of Journalism and is also a member of the Association of Business Executives (ABE).
